Males engage in mock combat and real fights during the rut. A male joins a group of females which he thus defends from other males. Stags lose weight rapidly because they don't eat while they defend the harem, and they are succeeded by new stags as the rut continues. After leaving the harem, the male begins to feed again, and will quickly regain his weight.
Mating System: polygynous
Sexual maturity for females is about 2 years and 3 months (Nowak, 1999), and males mature about a year later. About two months before breeding season in June, males will leave the herd. They will rejoin a harem of females and fast during the rut. When fighting, males will use antlers, teeth, and will even rise up on hind legs and box with their front legs. Females have an approximately 20 day long estrous cycle (Nowak, 1999), and within a breeding season can have multiple cycles. The gestation period is about 280 days and one or two fawns are born in April or May (Jiang et al., 2001). Fawns weigh about 11 kg at birth. After the rut, males will leave the herd again for another two months and begin feeding (Brinklow,1993).
Development in species has not been reported. The gestation period is unusually long, however, and an embryonic diapause may occur (Nowak, 1999).
Breeding season: Young are born in April and May.
Average number of offspring: 1-2.
Average gestation period: 9.33 months.
Average age at sexual or reproductive maturity (female): 27 months.
Average age at sexual or reproductive maturity (male): 27 months.
Key Reproductive Features: seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization (Internal ); viviparous
Average birth mass: 11000 g.
Average gestation period: 288 days.
Average number of offspring: 1.
Average age at sexual or reproductive maturity (male)
Sex: male: 1186 days.
Average age at sexual or reproductive maturity (female)
Sex: female: 821 days.
As in all mammals, the female provides the young with milk.
Parental Investment: female parental care